Polymorphism refers to such a phenomenon that solid states with different physicochemical properties formed by solid substances in two or more different spatial arrangements. In the field of drug research, polymorphs also include multi-component crystal forms, such as organic solvates and hydrates. Crystalline research and control are important research contents in drug development.
Inositol Nicotinate, chemically named cis-1,2,3,5-trans-4,6-cyclohexanehexol niacinate, is a mild peripheral vasodilator, after absorption, it is gradually hydrolyzed into nicotinic acid and inositol in vivo, and it has the pharmacological effects of both niacin and inositol. Its vasodilating effect is milder and longer lasting than niacin, and it can selectively expand blood vessels in lesions and sensitive areas that are stimulated by cold, while the expansion for the normal blood vessels is weaker. In addition, it also has the effects of thrombolysis, anticoagulation, anti-fatty liver, and reduction of capillary fragility, without the side effects such as flushing and stomach discomfort after taking niacin. Clinically, inositol nicotinic acid ester tablets are mainly used for auxiliary treatment of hyperlipidemia, atherosclerosis, and various peripheral vascular disorders (such as occlusive arteriosclerosis, acra arterial spasm, frostbite, vascular migraine, etc.)
The structure of inositol nicotinate is as shown below:

Inositol nicotinate is only soluble in hot dimethylformamide or dimethyl sulfoxide. It is very slightly soluble in chloroform and insoluble in water, ethanol and other organic solvents. No crystal form has been reported for this compound. The synthesis of inositol nicotinate is generally obtained by the condensation of inositol and nicotinic acid using pyridine as a solvent. Due to poor solubility, product purification and removal of residual pyridine are extremely difficult, while as high boiling point solvents, the use of dimethylformamide or dimethyl sulfoxide in crystallization and purification can also lead to the excessive residue of the solvent of dimethylformamide or dimethyl sulfoxide.